Aromatic tertiary amines, enamines, deoxybenzoins and benzils

ABSTRACT

A novel synthesis of aromatic tertiary amines involves reacting an aromatic anil and an aromatic ether in a molar ratio of 1:1; adjusting the ratio to 2:1 produces novel enamines and by employing a two step process for enamine production, various unsymmetrically substituted enamines can be obtained which are readily hydrolyzed to corresponding deoxybenzoins which in turn are readily oxidized to benzils, the aromatic tertiary amines may be used to produce charge transport layers in xerography, while the benzils may be used to produce a variety of desired polymers.

This is a continuation of application Ser. No. 475,992, filed Feb. 6,1990, now U.S. Pat. No. 5,011,998.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to novel syntheses of aromatic tertiary aminesand aromatic enamines as well as to novel aromatic enamines and thesyntheses therefrom of deoxybenzoins and benzils.

2. Description of Prior Art

The "anil" reaction of Scheme 1 developed by Siegrist (A. E. Siegrist etal, Advances in Heterocyclic Chemistry 23, 171 (1978)) has been utilizedfor the synthesis of a large number of substituted stilbenes (3) by thecondensation of an anil (1) with a methyl-containing aromatic compound(2). The aryl groups Ar, Ar' and Ar" can be hydrocarbon or a widevariety of heterocyclic groups. The reaction ##STR1## takes place in thepresence of strong bases such as potassium tert-butoxide or powderedpotassium hydroxide in N,N-dimethylformamide solution at 25°-100° C. andsince the aromatic amine (4) is the coproduct in the reaction thestrongly basic conditions are maintained in the reaction. The reactionhas also been utilized in Scheme 2 for the synthesis of2-phenylbenzofuran (6) by the intramolecular condensation of theSchiff's ##STR2## base (5) derived from 1-formyl-2-benzyloxybenzene andaniline, (W. Sahm et al Justus Liebigs Ann. Chem., 523 (1974).

Aromatic tertiary amines have previously been described for theproduction of charge transport layers in xerography in U.S. Pat. Nos.4,115,116; 4,047,948; 4,047,949; 4,081,274 and 4,232,103 and polymerscontaining these amine moieties have been synthesized (U.S. Pat. Nos.4,806,443 and 4,806,444).

SUMMARY OF THE INVENTION

It is an object of this invention to provide a novel synthesis ofaromatic tertiary amines.

It is a further object of this invention to provide aromatic tertiaryamines for use in the production of charge transport layers inxerography.

It is a further object of this invention to provide novel syntheses forthe production of aromatic enamines.

It is yet another object of this invention to provide a novel synthesisfor the production of aromatic enamines from aromatic tertiary amines.

It is still another object of this invention to provide a novelsynthesis of aromatic enamines from aromatic anils and aromatic ethers.

It is yet another object of this invention to provide novel aromaticenamines.

It is a still further object of this invention to provide a process forproducing deoxybenzoins.

It is yet another object of this invention to provide a process forproducing benzils.

In accordance with this invention it has surprisingly been found thatreacting an aromatic ether with an aromatic anil in a substantially 1:1molar ratio produces an aromatic tertiary amine.

In view of the reaction of Scheme 2 referred to hereinbefore suchreaction would have been expected to produce an enol ether rather thanan aromatic tertiary amine.

It has additionally been found that aromatic enamines are by-products ofthe reaction, but that when the molar ratio of the anil to the ether isincreased to 2:1, the enamine becomes the major product.

The aromatic enamine is readily hydrolysed to a correspondingdeoxybenzoin and secondary aromatic amine thereby providing a newsynthesis for a wide range of deoxybenzoins.

Deoxybenzoins are readily oxidized to corresponding benzils therebyproviding a facile and economically viable synthesis of benzils fromreadily available starting materials.

DESCRIPTION OF PREFERRED EMBODIMENTS i) Aromatic Tertiary Amines

The process of the invention provides for the preparation of aromatictertiary amines of formula (I): ##STR3## by reacting an aromatic anil offormula (II) with an aromatic ether of formula (III): ##STR4## whereinAr₁, Ar₂, Ar₃ and Ar₄ are each aromatic radicals independently selectedfrom: ##STR5## wherein x and y are integers independently selected from0, 1, 2 or 3, z is an integer independently selected from 0, 1 or 2 andR, R' and R" are each independently selected from halogen atoms selectedfrom fluorine, chlorine and bromine; alkyl of 1 to 6 carbon atoms,alkenyl of 2 to 6 carbon atoms; aryl of 6 to 12 carbon atoms, aralkyl of7 to 18 carbon atoms; aralkenyl of 8 to 18 carbon atoms; alkoxy of 1 to6 carbon atoms; thioalkoxy of 1 to 6 carbon atoms; aryloxy of 6 to 12carbon atoms and thioaryloxy of 6 to 12 carbon atoms.

This process is, in particular, carried out employing a molar ratio ofthe anil (II) to the ether (III) of 1:1 or about 1:1, at a temperatureof 20 to 100° C., in a basic, anhydrous medium.

In particular, the medium suitably comprises a polar, aprotic organicsolvent, for example, dimethylformamide, dimethylacetamide orN-methylpyrrolidone, which is rendered strongly basic. In particular,the strong basic character may be achieved by the presence of a strongbase, for example, sodium or potassium tert. butoxide, sodium amide orsodium dimethyl amide the latter may optionally be generated in situfrom sodium in N,N-dimethylformamide. Mixtures of such ases may beemployed.

It has been suggested that the known Wittig rearrangement ofbenzylphenyl ether of Scheme 3: ##STR6## proceeds by a mechanisminvolving the intermediary of a radical pair 7 including a radicalanion, which pair collapses to the alkoxide of the diarylcarbinol 8.

Based on this mechanism, a possible mechanism for the process of thisinvention is that a similar radical anion undergoes electronic transferwith the aromatic anil to produce an aromatic amine radical anion and anaromatic aldehyde which new radical anion collapses with the arylradical of the pair according to Scheme 4: ##STR7##

This synthesis of aromatic tertiary amines is much simpler than existingsyntheses which require a large number of steps. Additionally it ispossible to produce non-symmetric aromatic tertiary amines by the methodof the invention.

The aromatic tertiary amines may be used in the preparation of chargetransport layers in xerography, as well as in the production of aromaticenamines in another aspect of the invention.

ii) Aromatic Enamines

The novel aromatic enamines of this invention may be represented byformula (V): ##STR8## and within this class enamines of the formula(IV): ##STR9## in which Ar₁, Ar₂, Ar₃ and Ar₄ are as defined previouslyand R₅ is alkyl of 1 to 8 carbon atoms or a radical Ar₆, wherein Ar₆ isindependently selected from the same class of values as set forth forAr₁, Ar₂, Ar₃ and Ar₄.

The enamines (IV) are produced by reacting the previously describedaromatic anil (II) and aromatic ether (III) in a molar ration of 2:1 orabout 2:1. This reaction is suitably carried out at a temperature of 20°to 100° C. in the presence of a strong base and an anhydrous medium asdescribed above for the preparation of the aromatic tertiary amines (I).In this case both radicals Ar₁ are the same.

The broader class of enamines (V) can be produced by reacting anaromatic anil (II) with an aromatic tertiary amine (I) in which case R₅is the radical of formula Ar₆, and R₁ and R₄ can be the same ordifferent; or by reacting the aromatic anil (II) with an aromatictertiary amine of formula (VII): ##STR10## in which Ar₃ and Ar₄ are asdefined above and Alk is alkyl of 1 to 7 carbon atoms.

The tertiary amines of formula (VII) may be prepared by knowntechniques, for example, the benzylation of an N-alkylaniline with abenzyl chloride or benzyl bromide, with appropriate substituents R₃ andR₄ in the aromatic nuclei of the reactants.

The aromatic tertiary amines (I) may be prepared by the process of theinvention or by benzylation of diarylamines with a benzyl chloride orbromide, it being understood that the reactants have the appropriatesubstituents R₁, R₂ and R₃ in their nuclei.

iii) Deoxybenxoins

Hydrolysis of the enamines (IV) and (V) produces the correspondingdeoxybenzoins (VIII) and (IX) respectively: ##STR11## wherein Ar₁ andAr₄ are as defined above.

This hydrolysis proceeds readily under mild acid conditions, forexample, by heating under reflux in a solvent such as tertrahydrofuranin the presence of a mineral acid such as hydrochloric acid or sulphuricacid.

A secondary amine of formula (XXI): ##STR12## wherein Ar₃ and R₅ are asdefined above, is formed as a by-product of the hydrolysis of theenamine. This secondary amine (XXI) may be benzylated with an arylhalide of formula (XXII):

    Ar.sub.4 --CH.sub.2 X                                      (XXII)

wherein Ar₄ is as defined above and X is Cl or Br, to generate anaromatic tertiary amine of formula (XX): ##STR13## wherein Ar₃, Ar₄, andR₅ are as defined above; and this tertiary amine (XXIII) may be reactedwith an anil of formula (II) as described above, in a molar ratio of atleast approximately 1:1, and at a temperature of 20° to 100° C., therebyregenerating the enamine of formula (V).

iv) Benzils

Oxidation of the deoxybenzoins (VIII) and (IX) produces thecorresponding benzils (X) and (XI), respectively: ##STR14##

The oxidation of deoxybenzoins to benzils can be carried out by severalmethods. The most commonly used method utilizes selenium dioxide as theoxidizing agent (for a review see Comprehensive Organic Chemistry,Volume I, pp. 1201-3, Pergamon Press, 1979). More recently, M. B. Floyd,M. T. Du, P. F. Fabio, L. A. Jacob and B. D. Johnson (J. Am. Chem. Soc.1987, 50, 5022) utilized aqueous hydrobromic acid in dimethyl sulfoxideto oxidize acetophenones and deoxybenzoins to arylglyoxals and benzils,respectively.

These benzils are useful in the synthesis of polyquinoxalines, hinderedpolyphenyls and highly substituted phthalic anhydrides, which react withdiamines to produce polyimides as illustrated in the following:##STR15##

Benzil readily undergoes a condensation reaction with diphenylacetone toyield tetraphenyl-cyclopentadienone which then will undergo aDiels-Alder reaction with maleic anhydride to give tetraphenylphthalicanhydride. (cf. Organic Synthesis, Coll Vol. 3, pp. 806-808). It is thusfeasible to synthesize bis-dianhydrides from the appropriate tetraketonewhich can then be used as monomers for the synthesis of ##STR16##polyimides and other polymers. Tetraphenylcyclopentadienones alsoundergo a Diels-Alder reaction with acetylenes (Ar₁₀ =Ar₁₁ =H or aryl,Ar₁₂ =arylene) to give the completely aromatic structure, e.g. reactionwith tolan yields hexaphenylbenzene in very high yield. This reactionhas also been utilized to synthesize polyphenyls by reaction of theappropriate bis(tetraphenylcyclopentadienone) with bis-acetylene. (J. K.Stille and G. K. Noren J. Pol. Sci., Pol. Lett. Ed. 7, 525, (1969)).

Benzils also condense readily with o-phenylenediamines to givesubstituted quinoxalines and this reaction has been utilized tosynthesize high molecular weight polyquinoxalines by starting with theappropriate tetraketone and tetraamine. (J. K. Stille, U.S. Pat. No.3,661,850, 1972; W. Wrasidlo and J. M. Augl, Macromolecules 3, 544(1970). ##STR17##

The substituents R, R' and R" may be located in any position of thearomatic radicals Ar₁, Ar₂, Ar₃, Ar₄ and Ar₆, for example, the o, m or pposition, of their respective aromatic nuclei, and such nuclei may bemono- di- or tri-substituted by the values R₁, R₂, R₃, R₄ and R₆ (otherthan hydrogen atoms). It will be understood that in the case of di- ortri-substitution the R, R' and R" substituents may be the same ordifferent.

The invention is further illustrated in particular and preferredembodiments by reference to the following examples.

EXAMPLES Experimental General procedure for the preparation of thesodium/dimethylformamide (Na/DMF) mixture

To dimethylformamide (40 of 50 ml) was added sodium (1.0 g, 0.043 mol)in seven portions at 105°-110° C. under a slow stream of nitrogen andwith stirring. Additional portions of sodium were introduced after theinitial vigorous reaction had abated. The mixture was brought to thedesired temperature and the substrates were added using the remainingvolume of dimethylformamide to dissolve them.

General procedure for the preparation of Anils:N-(Phenylmethyl)benzeneamine

Benzaldehyde (31.84 g, 0.300 mol) and aniline (27.94 g, 0.300 mol) inbenzene (100 ml) were heated to remove the water using a Dean-Starktrap. After 5.4 ml of water had been collected, the benzene was strippedoff and the residual oil poured into a beaker. On treating withpetroleum ether (10-20 ml) the oil crystallized. This mass was suctionfiltered and washed with some additional petroleum ether.Recrystallization from hexane gave off-white needles.

General Procedure for preparing the arylbenzyl ethers.

The arylphenoxide (anhydrous, 0.30 mol) and an equivalent amount ofbenzylchloride were heated to 80° C. for 1.5 hr in dimethylformamide(100 ml). The ether was precipitated by addition of water, 300 ml,filtered and dried. This produce was usually pure enough for the nextreaction. Recrystallization from ethanol, 95%, gave the pure benzylethers.

4,4'-Bis(benzyloxy)1,1'-biphenyl

This diether is produced in one step using the same procedure above(methanolic KOH was used) in>90% yield, mp 222°-224° C. from benzene.FTIR (KBr wafer)γ:3092, 3064, 3048, 3034, 2939, 2906, 2864, 1608, 1508,1500, 1469, 1455 cm⁻¹ ; MS[m/e (70 eV, % of base peak)](PhCH6H₄ --C6H4)366 (M⁺, 25.9), 275 (M⁺ --PhCH2, 15.8), 91 (PhCH2⁺, 100).

Example 1 N,N-Diphenylbenzenemethanamine ##STR18##

N-phenylbanzaldimine (1.81 g, 0.010 mol) and benzylphenyl ether (1.84 g,0.010 mol) were heated at 75° C. in Na/DMF solution (2.0 g; 50 mL) for30 minutes. The solution was then poured in 200 mL of water, theprecipitate was filtered washed with water and dried. Recrystallizationfrom methanol, 70 mL, gave white needles (73% isolated) mp 88°-90° C.(lit mp 86°-7°C⁸, 88°-9°C⁹). No depression in melting point occurredwhen this material was admixed with an authentic sample prepared fromdiphenylamine and benzyl chloride.

Byproducts in the preparation of N,N-diphenylbenzene-methanaminereaction at 100° C

The mother liquors from the recrystallization ofN,N-diphenylbenzenemethanamine were combined with the petroleum etherextracts 3×150 mL of the aqueous dimethyl formamide filtrate. Theorganics were evaporated and the residual oil chromatographed on 25 g ofsilica. The first eluent was petroleum ether giving one major fractionalmixture containing some more benzyldiphenylamine. Other fractionscrystallized some material mp 203°-4° C. (m/e=181) which was notcharacterized further. The later fractions contained some material mp168°-70° C from methanol. A mass spectrum of this last compound appearsconsistent with m/e=197 for N-phenylbenzamide.

The initial aqueous dimethylformamide solution was extracted withchloroform 3×150 mL. The solvent was evaporated and the residual oil waschromatographed on 30 g of silica with ethyl acetate/petroleum ether1:1. The last fractions upon concentration and cooling slowlycrystallized some material which was washed with ether and crystallizedfrom the same mp 134°-7° C. as colorless needles. The spectra areconsistent with the literature¹⁰ for N,N-dimethyl-N'-phenylurea mp132°-3°C¹¹ and 131°-2°C¹². The middle fraction was chromatographed on 60g of silica using the same eluent to give a small amount ofN,N-dimethyl-α-(phenylamino)benzeneacetamide (see above). Also an impureoil was characterized by comparing the FTIR andmass-spectrum-fragmentation pattern of an Aldrich sample ofN,N-dimethylbenzamide. Only in the infrared spectrum there was evidence,from N--H and C═O stretching bands, that at least another product wascontaminating the N,N-dimethylenzamide.

Example 2 N,N-Diphenyl-1-naphthalenemethanamine ##STR19##

N-phenylnaphthaldimine (2.20 g, 0.010 mol) and benzylphenyl ether (1.84g, 0.010 mol) were reacted as above for the preparation ofbenzyldiphenylamine. Aqueous work-up afforded a precipitate which wasisolated by filtration and recrystallized from 95% ethanol to yield 2.3g (74%) of needles, mp 170°-172° C. Anal. calcd. for C23H19N: C 89.28, H6.19, N 4.53%; found: C 89.11, H 6.26, N 4.44%. 1H NMR (200 MHz, CDCl3)δ(assignment): 5.52 (s, 2H, CH2), 7.00-8.10 (m, 17H, aromatic). MS [m/e(70 ev, % of base peak)](C10H7)CH2N(C6H5)2 309 (M+., 4.8), 308 (M+--H.,29.0), 168 (M+--((C10H7)CH2)., 18.0), 141 (((C10H7)CH2)+., 100 ). FTIR(CDCl3): 3063, 3040, 1606, 1602, 1594, 1584, 1574, 1559, 1512, 1501,1497, 1488, 1485, 1474, 1465, 1460, 1451 cm⁻¹.

Example 3 N(4-Methoxyphenyl)-N-phenyl-1-naphthalenemethanamine ##STR20##

N-phenylnaphthldimine (2.20 g, 0.010 mol) and benzyl-4-methoxyphenylether (2.14 g, 0.010 mol) were reacted in Na/DMF solution (50 mL) at100° C. for 30 min. A similar work-up as for the preparation ofbenzyldiphenylamine gave 0.50 g. of product (15%) which afterrecrystallization from hexane had mp 154°-159° C. ¹ H NMR (200 MHz,CDCl3) δ(assignment): 3.79 (d, J=1.40 Hz, 3H, OCH3), 5.39 (s, 2H, CH2),6.78-6.89 (m, 5H, aromatic), 7.16-8.07 (m, 11H, aromatic). MS [m/e (70eV, % of base peak)](C10H7)CH2N(C6H5(CH3O(C6H4)) 339 (M+., 23.0), 198(M+--((C10H7)CH2)., 58.3), 141 ((C10H7)CH2)+., 100). Analysis: Calcd.for C24H21NO: C 84.92, H 6.24, N4.13 %; found (average of two runs); C85.06, H 6.61, N 3.99%.

Example 4 Bis[4-(N,N-diphenylaminomethyl)phenoxy]methane ##STR21##

Di(N-phenylcarboxaldimine-4-phenoxy) methane (2.03 g, 0.0050 mol) andbenzylphenyl ether (1.84 g, 0.010 mol) were heated in Na/DMF solution(50 ml) at 100° C. for one hours. Similar work-up as for the preparationof benzyldiphenylamine, double chromatography on silica using carbontetrachloride as eluent gave 0.40 g (14%) of the title compound, mp99°-100° C. from hexane. Analysis calcd. for C39H34N2O2; C 83.24, H6.09, N 4.98%; f found: C 83.44, H 6.14, N 4.96%. ¹ H NMR (200 MHz,CDCl3) δ(assignment): 4.96 (s, 4H, CH2N), 5.67 (s, 2H, OCH2O), 6.90-7.09(m, 16H, aromatic), 7.20-7.30 (m, 12H, aromatic). FTIR (CDCl3): 3098,3075, 3045, 1604, 1591, 1575, 1507, 1498 cm⁻¹.

Example 5N-[4-(1,1-dimethylethyl)phenyl]-N-phenyl-naphthalenemethanamine##STR22##

N-phenylnaphthaldimine (2.20 g, 0.010 mol) and benzyl-t-butylphenylether(0.01 mol) were reacted in Na/DMF solution (50 ml) at 100° C. for 30min. The usual work-up followed by chromatography on silica usingpetroleum ether/chloroform 4:1 as eluent gave, after crystallizationfrom petroleum ether/methanol, 1.3 g (36%) of the title compound, mp135°-137° C. as prisms. Anal. calcd. for C27H27N: C 88.72, H 7.44, N3.83%, found: C 88.50, H 7.49, N 3.76 %. ¹ H NMR (200 MHz,CDCl3)δ(assignment): 1.29 (d,J=1.20 Hz, 9H, C(CH3)3), 5.45 (s, 2H,CH2N), 6.86-8.04 (m, 16H, aromatic). MS [m/e (70 eV, % of basepeak)](C10H7)CH2N(C6H5)((C6H4)C(CH3)3) 365 (M+. 18.9), 350 M+--CH₃,10.6), 141 (C10H7CH2⁺, 100). FTIR (CDCl3) V: 3063, 3040, 2966, 2904,2870, 1596, 1515, 1512, 1500, 1496, 1477, 1459 cm⁻¹.

Example 6 N-)1-napthyl)-N-phenyl-nephthalenemethanamine ##STR23##

(1-Naphthylmethoxy)-1-naphthalene (2.84 g, 0.010 mol) andN-phenylnaphthaldimine (2.20 g, 0.010 mol) were reacted in Na/DMF (1 g;50 mL) at 75° C. for 30 min. Aqueous work-up afforded a stickyprecipitate which was dissolved in ether treated with 7.0 g of silicaand the ether was evaporated. This dry silica was added to a bed of ˜40g of silica wetted with petroleum ether/ethyl acetate 98:2 and elutedwith the same solvent. The fractions containing the title compound werecombined. After evaporation of the solvent the residue wasrecrystallized from ethyl acetate mp 179°-80° C. (65% based on acalibration graph).¹ H NMR (200 MHz, CDCl₃)δ(assignment): 5.47 (s, 2 H,NCH2Ph), 6.56-6.77 (m, 3 H, aromatic). MS [m/e (70 eV, % of basepeak)]C10H7CH2N(C10H7)(Ph) 359 M⁺, 31.6), 218((C10H7NPh)⁻, 31.2), 141(C10H7N⁺, 100); HRMS (m/z) for C27H21N (M⁺) calcd. 359,167 found369.183. FTIR (CDCL3): 3061, 2890, 2852, 1599, 1575, 1499, 1470, 1398cm⁻¹.

Example 7N,N'-Diphenyl-N,N'-bis(phenylmethyl)[1,1'-biphenyl]-4,4'-diamine##STR24##

N-Phenylmethylene)benzenamine (3.62 g, 0.020 mol) and4,4'-bis(phenylmethoxy)[1,1'-biphenyl](3.66 g, 0.010 mol) were heated inNa/DMF solution (50 mL) at 100° C. for 1 hr. High pressure liquidchromatography indicated a complex mixture from which three products: I(14%), II (10%), and III (8%), were isolated and identified as follows.The Na/DMF mixture was poured into water (100 ml) and extracted withchloroform (3×100 mL). After drying over sodium sulfate, the organicphase was evaporated under reduced pressure. The resulting oil waschromatographed on silica (60 g ) using petroleum ether/chloroform 4:1as eluent separating pure I and a mixture of II and III. Compound I hadmp 89°-91° C. from petroleum ether/methanol which was not depressed withan admixture of N,N-diphenylbenzenemethanamine and showed an identicalmass-spectrum-fragmentation pattern of this amine. The mixture of II andIII was chromatographed on silica (60 g) with the same eluent above togive the separated materials. ##STR25##

Compound II, the less polar, was recrystallized from ethylacetate/methanol mp 136°-137° C. Its mass spectra are consistent withthe title compound: MS[m/e (70eV, % of base peak)][PhCH2(Ph)N]2(C6H4--C6H4) 516 (M⁺•, 96.2), 425 (M⁺ --PhCH2.sup.•, 100), 334 (M⁺•--2PhCH2.sup.•, 56.7), 91 (PhCH2⁺•, 61.7); m/2) for C38H32N2 (M⁺),calcd. 516.256, found 516.27. Analysis calcd. for C38H32N2: C 88.33, H6.24, N 5.42 %; found (average of two runs): C 88.30, H 6.61, N 5.40%.HRMS FTIR (KBr wafer) γ3084, 3058, 3051, 3048, 3031, 3006, 1593, 1508,1499, 1497, 1450 cm⁻¹. Compound III above was crystallized fromchloroform/methanol and had a wide decomposition range: 137°-150° C. Itsmass spectra are consistent with4'-(Phenylmethoxy)-N-phenyl-N-(phenylmethyl)[1,1'-biphenyl]-4-amine: MS[m/e (70eV, % of base peak)] PhCH2O(C6H 4--C6H4)N(Ph)CH2Ph 441 (M⁺•,23.3), 350 (M⁺ --PhCH2•, 39.4), 91 (PhCH2⁺•, 100); HRMS (m/2) forC32H27NO: calcd. 441.209, found 441.222.

Example 8 N-(4-methylphenyl)-N-phenyl-benzenemethanamine ##STR26##

Methyl-4-(phenylmethoxy)benzene (1.98 g, 0.01 mol) andN-(phenylmethylene)benzenamine (1.81 g, 0.01 mol) were reacted in Na/DMF(1 g: 50 mL) at 75° C. for 30 min. Aqueous work-up, extraction withpetroleum ether, 3×100 mL, and chromatography with petroleum ether/ethylacetate 95:5 afforded a total of 1 g. of solid which by HPLCchromatography contained N,N-diphenyl-benzenemethanamine and the titlecompound in the ratio 6:94 (51% yield by HPLC). The purer fractions fromchromatography on silica were combined and the solvent removed. Theresidual oil was dissolved in methanol and some petroleum ether. Oncooling this crystallized the title compound. Two recrystallizationsfrom methanol gave the title compound (98.1% pure; 36% yield), mp 85°-6°C. ¹ H NMR (200 MHz, CDCl3) δ(assignment): 2.29 (s, 3H, methyl), 4.97(s, 2H, --NCH2Ph), 6.80-6.97 (m, 3H, aromatic) 7.06-7.27 (d, 4H, J=1.37Hz, --NC6H4CH3), 7.14-7.36 (m, 7H, aromatic). MS [m/e (70 eV, % of basepeak)]PhCH2N(Ph)(C6H4)CH3 272 (M⁺•, 96.5), 196 (M⁺• --Ph^(`), 31.7), 182(M⁺• --PhCH3 •, 100), 167 (M⁺• --PhCH2 •--CH3•, 81.2), 91 (C7H7⁺, 98.3).FTIR (CDCL3): 3089, 3064, 3030, 2924, 2864, 1596, 1572, 1512, 1497, 1453cm⁻¹.

Example 9 N-(2-methylphenyl)-N-phenyl-benzenemethanamine ##STR27##

Methyl-2-phenylmethoxybenzene (1.98 g, 0.010 mol) andN-(phenylmethylene)benzeneamine (1.81 g, 0.010 mol) were reacted inNa/DMF (1 g: 50 mL) at 75° C. for 30 min. Aqueous work-up, extractionwith petroleum ether, 3×100 mL, and evaporation of the solvent gave asolid residue. This material was treated with a little ether to leave awhite crystalline compound (36% yield) which was recrystallized frommethanol to give the title compound mp 101°-2° C. ¹ H NMR (200 MHz,CDCl3) δ(assignment): 2.15 (s, 3 H, methyl), 4.84 (s, 2 H, PhCH2N),6.50-6.56 (m, 2 H, aromatic), 6.66-6.77 (m, 1 H, aromatic), 7.07-7.42(m, 11 H, aromatic). MS [m/e (70 eV, % of base peak)] PhCH2N(Ph)C6H4CH3273 (M⁺•, 100), 182 M⁺• --PhCH3+•, 74.1), 180 (PhCNPh)⁺, 55.4), 91(C7H7³⁰ , 75.4), 77 (Ph⁺•, 48.4); HRMS (m/z) for C20H19N (M⁺•), calcd.273.152, found 273.1. FTIR (CDCl3): 3088,3065,3028, 2980, 2953, 2928,2889, 2852, 1598, 1530, 14978, 1455, 1441, 1375, 1348, 1297, 1258, 1231cm⁻¹. Analysis: Calcd. for C20H19N: C 87.87 H 7.00, N 5.12 %;found(average of two runs); C 87.85, H 7.23, N 5.05%.

Example 10 N-(4-Chlorophenyl)-N-phenyl-benzenemethanamine ##STR28##

Chloro-4-(phenylmethoxy)benzene (2.18 g, 0.010 mol) andN-(phenylmethylene)benzenamine (1.81 g, 0.010 mol) were reacted inNa/DMF (1 g: 50 mL) at 50° C. for 7 hrs. The reaction was followed byHPLC to about 90% conversion. This technique indicated among otherthings the presence of the title compound, benzyldiphenylamine, and someunknown material in a ratio 65:18:17. Similar aqueous workup as for thepreparation of benzyldiphenylamine and chromatography on silica gave0.50 g of the title compound mp 94°-5° C. from methanol (lit⁸ mp97°-7.5° C. 70% yield). This material is contaminated with a smallamount of diphenylbenzylamine. ¹ H NMR (200 MHz, CDCl3) δ(assignment):5.03 (s, 2H, Ph2NCH2Ph), 6.96-7.38 (m, 14H, aromatic). MS [m/e (70 eV, %of base peak)]C19H16ClN 293 (M⁺•, 52.8), 295 (M⁺• +2, 28.8), 202 (M⁺--C7H7⁺, 22), 167((C6H4NPh)⁺•, 48.3), 91 (C₇ H₇ ⁺, 100). FTIR (CDCl3):3066, 3033, 1589, 1494, 1454 cm⁻¹.

Example 11 N-(4-Bromophenyl)-N-phenyl-benzenemethanamine ##STR29##

Bromo-4-(phenylmethoxy)benzene (2.63 g, 0.010 mol) and N-(phenyl-methylene)benzeneamine (1.81 g, 0.010 mol) were dissolved in Na/DMF (1g: 50 mL) and heated at 50° C. for 145 min. Two other reactions were runon the same molar ratios at 100° C. for 15 min and at 30° C. for 24 hrs.The reactions were monitored by HPLC. After the stated periods the titlecompound and benzyldiphenylamine were produced in the following ratios:at 100° C. 31:69, at 50° C. 77:33, and at 30° C. 94:6. The conversiondecreased with temperature at 100° C.˜100% at 50° C.˜95% at 30° C.˜50%.Aqueous workup of the reaction run at 30° C. and chromatography onsilica obtained the title compound (98% pure; 77% yield)), mp 97-8° C.from petroleum ether/methanol. ¹ H NMR (200 MHz, CDCl3) δ(assignment):4.96 (s, 2H, --NCH2Ph), 6.83-6.88 (m, 2H, aromatic), 7.01-7.32 (m, 12 H,aromatic. MS [m/e (70 eV, % of base peak)]Ph(BrC6H4)NCH2Ph 337 (M⁺•,45.4), 339 (M⁺• +2, 46.3), 167 (M⁺• --PhCH2--Br, 42.5), 91 (C7H7⁺, 100).FTIR (CDCl3): 3089, 3066, 3033, 2919, 2868, 1601, 1584, 1499, 1493,1487, 1453 cm⁻¹.

Example 12 Bix[4-(N-phenyl(phenylmethylamino)) phenyl]-2,2-propane##STR30##

Bis [4-(phenylmethoxy)phenyl]-2, 2-propane (2.04 g, 0.005 mol) andN-(phenylmetylene)benzenamine (3.62 g, 0.020 mol) were heated at 75° C.for 5 hrs in Na/DMF (1 g: 50 mL). After this period it was estimatedfrom HPLC that the ratio of N-(phenylmethylene)benzenamine,N,N-diphenylbenzenemethanamine,2-[4-(N-phenyl-(phenylmethylamino))phenyl]-2-[4-(phenylmethoxy)phenyl]propane(not isolated,) the title compound, and a unknown substance (with longerretention time) to be 0.006, 0.0014, 0.0004, 0.003, 0.0006 molrespectively. Aqueous workup precipitated a very viscous oil from whichthe liquid was decanted and the oil washed with water and methanolsuccessively. This oil was dissolved in diethyl ether and poured onto 10g of silica, the ether was evaporated off while stirring the mixture.The dried silica with adsorbed material was added to 50 g bed of silicawetted and packed with petroleum ether/benzene 98:2 as the eluent andthe material was chromatographed, the purer fractions containing thetitle compound were chromatographed once more. The cleaner fractionscontaining the title compound and the unknown 90:10 crystallized oncooling a low melting solid, mp 45°-50° C. (60% yield). MS [m/e (70 eV,% of base peak)](PhCH2(Ph)NC6H4)2C3H6 558 (M⁺•, 90), 543 (M⁺• --CH3,100), 468(M⁺• --PhCH2•, 30.9), 452 (M⁺• --CH3. --PhCH2. --H•, 31.1), 194(PhNC7H6CH3⁺•, 27.7), 91 (C7H7⁺, 50.5). FTIR (CDCl3): 3088, 3064, 3033,2971, 2938, 2872, 1595, 1510, 1497, 1453 cm⁻¹.

Example 13 N,N'-Diphenyl-N,N'-bis(phenylmethyl)benzene-1,4-diamine##STR31##

N,N'-Bis(phenylmethylene)benzene-1,4-diamine (1.42 g, 0.005 mol) andphenylmethoxybenzene (1.84 g, 0.010 mol) were heated in Na/DMF (1 g: 50mL) at 100° C. for 1 hr. Similar workup as for the preparation ofbenzyldiphenylamine and chromatography on silica using petroleumether/chloroform 4:1 as eluent gave 0.35 g (16%) mp 149°-51° C fromethyl acetate. ¹ H NMR (200 MHz, CDCl₃) δ(assignment): 4.96 (s, 4H,PhCH2N--), 6.80-6.97 (m, 6H, aromatic), 7.05 (s, 4H, (PhCH2(Ph)N)2C6H4),7.16-7.33 (m, 14H, aromatic). MS [m/e (70 eV, % of basepeak)](PhCH2(Ph)N)2C6H4 440 (M⁺, 25.4), 349 (M^(+--C) 7H7., 24.5), 91(C7H7⁺, 100). HRMS (M/Z) for C32H28N2 (M⁺) calcd. 440.225, found440.227.

Example 14 (E)-1-(diphenylamino)-1-phenyl-2-phenylethylene ##STR32##

Diphenylbenzylamine (3.92 g, 0.0151 mol) and N-phenylbenzaldimine (3.0g, 0.0165 nol) were heated for 150 min in dimethylformamide at 75° C.,50 mL, in the presence of potassium tert-butoxide (5.6 g, 0.050 mol).Based on reversed phase HPLC results, after 150 min the conversion was95% (i.e.˜6 of diphenylbenzylamine was unreacted). From a calibrationgraph the yield of the title compound was 75%. This material is isolatedby pouring the organic solution into water, 150 mL, and filtering theprecipitate. The sticky solid was treated with activated charcoal inboiling methanol filtered and cooled. The enamine crystallized slowly aspale green-yellow prisms mp 85°-7° C. ¹ H NMR (200 MHz, CDCl3)δ(assignment): 6.71 (s, 1 H, ═CHPh), 6.77-6.85 (m, 2 H, aromatic),7.05-7.38 (m, 16 H, aromatic) 7.56-7.62 (m, 2 H, aromatic), MS [m/e (70eV, % of base peak)]Ph2NC(Ph)CHPh 347 (M⁺•, 46.1), 180 (PhCNPh⁺ 100), 77(ph⁺, 29.7); HRMS (m/Z) for C26H21 N (M⁺•), calcd. 347.192, found347.180. FTIR (CDCl3): 3081, 3028, 1590, 1491, 1448 cm⁻¹. This materialwas further identified by hydrolysis (see below). Analysis: calcd. forC26H21N: C 89.89 H 6.09, N4.03 %; found (average of two runs): C 90.08,H 6.41, N 3.93%.

Example 15

Diphenylbenzylamine (1.30 g, 0.0050 mol) and N-phenylbenzaldimine (3.0g, 0.0165 mol) were heated at 75° C. for 17 h in the base systemtBuOH/DMF/Na 1.4 g; 50 mL: 1.0 g, which was prepared in situ from t-BuOH(1.4 g, 0.020 mol) DMF (25 mL) and sodium metal (1.0 g, 0.043 mol) at100°-110° C. (similar to the preparation of Na/DMF above). The enaminewas formed to about 54% of theory (from a calibration curve) based ondiphenylbenzylamine.

Example 16 Hydrolysis of (E)-1-diphenylamine-1-phenyl-2-phenylethyleneto Deoxybenzoin

(E)-1-(Diphenylamino)-1-phenyl-2-phenylethylene (1.0 g, 0.0029 mol) wasdissolved in tetrahydrofuran 30 mL and 1.2 M hydrochloric acid, 7.0 mL.On heating this solution two phases separated which disappeared oncooling. The progress of the reaction was monitored by reversed-phaseHPLC giving the disappearance of reactant and the appearance of products(only one signal appeared for the products). At the end of thehydrolysis, the solution was neutralized by adding an excess of solidsodium bicarbonate, filtered and evaporated. The residue waschromatographed on silica using petroleum ether/benzene/ethyl acetate,90:9:1, s eluent separating firstly diphenyl amine, mp 52°-3° C., frompetroleum ether and then deoxybenzoin, mp 55°-6° C. (lit. 55°-6°C¹³,56°C¹⁴), from petroleum ether. Their structures were confirmed bycomparison of spectra of the authentic materials.

Example 17 Oxidation of Deoxybenzoin to Benzil

To deoxybenzoin (4.91 g, 0.025 mol) dissolved in DMSO (42 mL) at 55° C.was added HBr (48% aqueous, 8.5 mL, 0.075 mol of HBr) and this solutionwas stirred overnight at 55° C. The solution was poured onto ice-water(300 mL) and cooled for 24 h. The precipitate was filtered, dried andweighed: 4.28 g (76%) mp 90°-94° C. Recrystallization from ethanol gave3.30 g (63%) of the title compound mp 95°-6° C.

Example 18 1-(diphenylamino)-1-phenyl-2-(1-naphthyl)ethylene ##STR33##

This compound was synthesized from diphenylbenzylamine andN-phenyl-1-napththaldimine under the same conditions outlined for(E)-1-(diphenylamino)-1-phenyl-2-phenylethylene above. Recrystallizationfrom ethyl acetate/methanol gave small crystals mp 170°-2° C. ¹ H NMR(200 MHz, CDCl3) δ (assignment): 6.60-6.90 (m, 2 H, aromatic), 6.80-7.38(m, 15 H, aromatic), 7.52-7.85 (m, 6 H, aromatic). MS [m/e (70 eV, % ofbase peak)]C10H7CHCPhNPh2 397 (M⁺•, 43.1), 180 (PhCNPh⁺, 100), 77 (Ph⁺,43.2); HRMS (m/z) for C30 H23N (M⁺•), calcd. 397.183 found 397.195.

Example 19 Hydrolysis of(E)-1-(diphenylamino)-1-phenyl-2(1-naphthyl)ethylene to 2-(1-Naphthyl)-1-phenylethanone ##STR34##

Refluxing (E)-N,N-diphenyl-1-phenyl-2-(1-naphthyl)ethyleneamine (impuresee above) in tetrahydrofuran, 30 mL, and 1.9 N H2SO4, 3.0 mL, for twohours and aqueous work-up as above gave a mixture of compounds. Theenamine was fully hydrolysed as indicated by reversed phase HPLC. Columnchromatography on silica 60 using petroleum ether/benzene/chloroform80:14:6 separated two fractions. The first containedN,N-diphenylbenzylmethanamine (unreacted) andN,N-diphenyl-(1-naphthalene)methanamine. The latter compound wasseparated pure by fractional crystallization from methanol mp 173°-5°C.: admixed with an authentic sample mp 171°-3° C. (Example 2) Thesecond fraction contained diphenylamine and was discarded. The thirdfraction was eluted by adding chloroform to the column. Afterevaporation of solvent, recrystallization from methanol gave the titlecompound as white plates mp 109°-10° C. (lit 106.5°-107°C¹³,109°-110°C¹⁵). FTIR (CDCl3): 3085, 3067, 3011, 2907, 1692(lit¹³ 1675(C═O, KBr)), 1598, 1581, 1511, 1448, 1417, 1399, 1330, 1275 cm⁻¹.

Example 20 (E)-1-(diphenylamino)-1-phenyl-2-phenylethylene fromBenzylphenyl Ether and N-Phenylbenzaldimine

Benzylphenyl Ether (1.84 g, 0.01 mol) and N-phenylbenzaldimine (4.34 g,0.024 nol) were heated at 75° C. for 2 hours in dimethylformamide, 50mL, int he presence of potassium tert-butoxide (5.6 g, 0.050 mol). Afterthis period the N-phenylbenzaldimine had decreased to about 10% of theoriginal amount and a 39% yield of the title compound was presentaccording to high pressure liquid chromatography using a calibrationgraph. After 17.8 hours the yield had increased to 44%.

Example 21 (E)-9-(1,2-diphenylethenyl)carbazole ##STR35##

N-Phenylbenzaldimine (1.35 g, 0.0075 mol) and 9-benzylcarbazole (1.29 g,0.0077 mol) were heated at 75° C. for 30 min in dimethylformamide (dry),50 mL, and potassium tert-butoxide (0.10 g, 0.00089 mol). Based onreversed-phase HPLC results, the reaction was complete after 3 min.Aqueous work-up as above and recrystallization of the precipitate frommethanol gave needles mp 160°-2° C. (81%). ¹ H NMR (200 MHz, CDCL3)δ(assignment): 6.85-7.09 (m, 2 H, aromatic). MS [m/e (70 eV, % of basepeak)]C26H19N 345 (M⁺•, 100), 267 (M⁺• --PhH, 25.8), 178 PhCCPh⁺•,47.5), 167 (carbazole⁺•, 63.6). HRMS (m/z) for C26H19N (M⁺•) calcd.345.1517 found 345.1513. FTIR (CDCl3): 3083, 3064, 3027, 1624, 1598,1493, 1479, 1450, 1384, 1335, 1314, 1232 cm⁻¹ . Analysis: calcd. forC26H19N: C 90.40, H 5.54, N 4.05%; found: C 90.25, H 5.66, N 4.20%.

Example 22 (E)-9(1,2-diphenylethenyl)carbazole

N-Phenylbenzaldimine (1.35 g, 0.0075 mol) and 9-benzylcarbazole (1.29 g,0.0077 mol) were heated at 75° C. for 30 min in Na/DMF (see above).Based on reversed-phase HPLC results and a calibration curve thereaction reaches a plateau value after 15 min. Aqueous work-up as aboveand recrystallization of the precipitate from methanol gave needles mp160°-2° C. (58%).

Example 23 (E)-N-Ethyl-N-phenyl-1,2-diphenyletheneamine ##STR36##

N-Benzyl-N-ethylaniline (2.11 g, 0.010 mol) and N-phenylbenzaldimine(2.00 g, 0.012 mol) were heated for 1 hr at 75° C. in dimethylformamide50 mL and potassium tert-butoxide (5.6 g, 0.05 mol). Aqueous work-up asabove, extraction with diethyl ether, and chromatography using 50 g ofsilica-60 with petroleum ether/benzene 8:2 (only 200 ml of solvent isneeded). After evaporation of the solvent the oil was analyzed and thencharacterized further by hydrolysis (see below). MS [m/e (70 eV, % ofbase peak)]C22H21N 299 (M⁺•, 39.7), 132 (M⁺• --Ph2CH•, 65.6), 104(PhNCH⁺, 58.4), 91 (C7H7⁺, 100); HRMS (m/z) for C14H12O (M⁺•) calcd.299.167 found 299.168 ¹ H NMR (200 MHz, CDCl3) δ(assignment): 1.25 (t, 3H, J=4.8 Hz, methyl), 3.55 (q, 2 H, --NCH2CH3), 6.67-6.81 (m, 3 H,aromatic), 6.75 (s, 1 H, ═CHPh), 7.11-7.54 (m, 12 H, aromatic). FTIR(CDCL3): 3083, 3063, 3028, 2975, 2935, 2873, 1598, 1574, 1500, 1497,1462, 1448, 1392, 1378, 1340, 1318 cm⁻¹.

Example 24 Hydrolysis of (E)-N-ethyl-N-phenyl-1,2-diphenyletheneamine toDeoxybenzoin

The enamine was reflexed in tetrahydrofuran 30 mL and 1.9 N sulfuricacid 3.0 mL for 1 hr. The solution was then treated with solidbicarbonate and the solvents were evaporated under reduced pressure. Theresidual oil was dissolved in diethyl ether and extracted with 1.9 NH2SO4 2×10mL, washed with water 10 mL, aqueous bicarbonate 10 mL, andwater 10 mL. The organic phase was filtered through sodium sulfate andthe solvent was evaporated under reduced pressure. The residual oil wasdissolved in boiling petroleum ether 30°-60° C. and cooled. Thisprocedure deposited 1,2-diphenylethanone 1.2 g (61% based on theN-ethyl-N-phenylbenzylamine) mp 54°-6°C.

Example 25(E),(E)-1,1'-[1,4-phenylene]bis-[2-phenyl-1-(diphenylamino)ethylene]##STR37##

N-phenylbenzaldimine (1.81 g, 0.01 mol) andN,N,N',N'-tetraphenyl-a,a'-(1.4-xylenediyl)diamine (2.20 g, 0.005 mol)were reacted in potassium tert-butoxide (5.6 g, 0.05 mol) anddimethylformamide 50 ml at 75° C. for approximately 1 hr. Aqueouswork-up precipitated the title compound which was recrystallized fromacetone. It was purified by column chromatography using petroleumether/benzene 98:2 as eluent. The yellow compound melts at 265°-8°C.from acetone. ¹ H NMR (200 MHz, CDCl3) δ(assignment): 6.68 (s, 2 H,=CHPh), 6.77-6.86 (m, 4 H, aromatic), 7.01-7.36 (m, 26 H, aromatic),7.49 (s, 4 H, phenylene hydrogens). MS [m/e (70eV, % of base peak)]616(M⁺•, 62.9), 615 (M⁺• --H•,91.1), 449 (M⁺• --Ph2CH•, 50), 448 (M⁺ •--Ph2N⁺, 100), 282 (PhNC(C6H4)CNPh⁺•, 55.5), 280 (PhCHC(C6H4)CCHPh⁺•,43.5). ¹ NHMR(200 MHz, CDCl3) δ(assignment): 6.68 (s, 2H═CHPh),7.01-7.36 (m 2 H), 7.19 (s, 4 H, phenylene). FTIR (CDCl₃) v: 3066, 3035,1590, 1492, 1447(w), 1408(w), 1353, 1327, 1310, 1293, 1277, 1230,1219(w) cm⁻¹.

Example 26 1,1'-(1,4-Phenylene)bis[2-phenylethanone] ##STR38##

Chromatographed(E),(E)-1,1'-[1,4-phenylene]bis[2-phenyl-1-(diphenylamino)ethylene](1.0g, 0.0016 mol) was refluxed in a solution of THF (30 mL) and aqueous HCl(1.2 M, 3.0 mL) for 1.25 h. The solution was worked-up as for thepreparation of 1,2-diphenylethanone. Chromatography on silica (30 g)eluting with petroleum ether/benzene 3:2 removed the diketone. Aftersolvent evaporation of the combined fractions and recrystallization ofthe residue from benzene/methanol gave small plates mp 171°-3° C. (85%).FTIR (CDCl₃)ν: 3089, 3066, 3033, 2900, 1592(C═O), 1676, 1568, 1492,1454, 1404, 1325, 1309, 1272, 1217, 1202 cm⁻¹. ¹ H NMR (200 MHz,CDCl₃)δ4.30(s, 4H, --CH₂ Ph), 7.24-7.37(m, 10 H, ending phenyls),8.06(s,4 H, phenylene).MS [m/e(70eV,% of base peak)]C22H18O2 314(M⁺•,0.8), 223(M⁺ • --PhCH2.sup.•, 100), 104(C₆ H₄ CO⁺, 42.9), 91(C7H₇ ⁺,29).

In this specification aromatic ethers is to be understood to mean aryl,arylmethyl ethers; and aromatic tertiary amines is to be understood tomean diaryl, arylmethyl tertiary amines.

We claim:
 1. A process for preparing aromatic tertiary amines of formula (I): ##STR39## comprising: reacting an aromatic anil of formula (II):

    Ar.sub.1 --CH═N--Ar.sub.2                              (II)

with an aromatic ether of formula (III):

    Ar.sub.4 --CH.sub.2 --O--Ar.sub.3                          (III)

wherein Ar₁, Ar₂, Ar₃ and Ar₄ are each aromatic radicals independently selected from: ##STR40## wherein x and y are integers independently selected from 0, 1, 2 or 3, z is an integer independently selected from 0, 1 or 2 and R, R' and R" are each independently selected from halogen atoms selected from F, Cl and Br, alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 18 carbon atoms, aralkenyl of 8 to 18 carbon atoms, alkoxy of 1 to 6 carbon atoms, thioalkoxy of 1 to 6 carbon atoms, aryloxy of 6 to 12 carbon atoms and thioaryloxy of 6 to 12 carbon atoms, in a molar ratio of about 1:1, at a temperature of 20° to 100° C., in a basic, anhydrous medium.
 2. A process according to claim 1, wherein said medium comprises a polar, aprotic organic solvent containing a strong base.
 3. A process according to claim 2, wherein said solvent is selected from N,N-dimethylformamide, dimethylacetamide and N-methylpyrrolidone.
 4. A process according to claim 2, wherein said strong base is selected from at least one of potassium tert. butoxide, sodium tert. butoxide, sodium amide, sodium dimethyl amide and sodium in N,N-dimethylformamide.
 5. A process for preparing an aromatic enamine of formula (IV): ##STR41## comprising: reacting an aromatic anil of formula (II):

    Ar.sub.1 --CH═N--Ar.sub.2                              (II)

with an aromatic ether of the formula (III):

    Ar.sub.4 --CH.sub.2 --O--Ar.sub.3                          (III)

wherein Ar₁, Ar₂, Ar₃ and Ar₄ are each aromatic radicals independently selected from: ##STR42## x and y are integers independently selected from 0, 1, 2 or 3 and z is an integer independently selected from 0, 1 or 2 and R, R' and R" are each independently selected from halogen atoms selected from F, Cl and Br, alkyl of 1 to 6 carbon atoms; alkenyl of 2 to 6 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 18 carbon atoms, aralkenyl of 8 to 18 carbon atoms, alkoxy of 1 to 6 carbon atoms, a thioalkoxy of 1 to 6 carbon atoms, aryloxy of 6 to 12 carbon atoms and thioaryloxy of 6 to 12 carbon atoms, at a temperature of 20°-100° C., in a molar ratio of said anil (II) to said ether (III) of about 2:1.
 6. A process according to claim 5, carried out in a basic, anhydrous medium.
 7. A process according to claim 6, wherein said medium comprises a polar, aprotic organic solvent containing a strong base.
 8. A process according to claim 7, wherein said solvent is selected from N,N-dimethylformamide, dimethylacetamide and N-methylpyrrolidone.
 9. A process according to claim 7, wherein said strong base is selected from at least one of potassium tert. butoxide, sodium tert. butoxide, sodium amide, sodium dimethylamide and sodium in N,N-dimethylformamide.
 10. A process for preparing an aromatic enamine of formula (V): ##STR43## comprising: reacting an anil of the formula (II):

    Ar.sub.1 --CH═N--Ar.sub.2                              (II)

with an aromatic tertiary amine of formula (XX): ##STR44## wherein Ar₁, Ar₂, Ar₃ and Ar₄ are each aromatic radicals independently selected from: ##STR45## x and y are integers independently selected from 0, 1, 2 or 3 and z is an integer independently selected from 0, 1 or 2 and R, R' and R" are each independently selected from halogen atoms, selected from F, Cl and Br, alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 18 carbon atoms, aralkenyl of 8 to 18 carbon atoms, alkoxy of 1 to 6 carbon atoms, a thioalkoxy of 1 to 6 carbon atoms, aryloxy of 6 to 12 carbon atoms and thioaryloxy of 6 to 12 carbon atoms, and R₅ is alkyl of 1 to 8 carbon atoms or a radical Ar₆, wherein Ar₆ is an aromatic radical as defined above for Ar₁, Ar₂, Ar₃ and Ar₄, at a temperature of 20°-100° C., in a molar ratio of said anil (II) to said aromatic tertiary amine (XX) of 1:1.
 11. A process according to claim 10, carried out in a basic, anhydrous medium.
 12. A process according to claim 11, wherein said medium comprises a polar, aprotic organic solvent containing a strong base.
 13. A process according to claim 12, wherein said solvent is selected from N, N-dimethylformamide, dimethylacetamide and N-methylpyrrolidone.
 14. A process according to claim 12, wherein said strong base is selected from at least one of potassium tert. butoxide, sodium tert. butoxide sodium amide, sodium dimethylamide and sodium in N,N-dimethylformamide. 